feat: ✨ route guards

[lucas-labs]

Alternate solution to #10 that doesn't require an implementation of route-controller level middlewares.

This implementation doesn't use starlette middlewares, but... it works.

• Implements controller/route level route guards.

class AuthGuard(Guard):
    def can_activate(self, request: Request, *, context: Any, set_result: GuardCb) -> bool:
        # guard logic

• Per-Controller guards.

@controller('/secure')
@use_guard(AuthGuard)
class Controller:
    ...

• Per-Route Controller.

@controller('/secure')
class Controller:
    @get('/')
    @use_guard(AuthGuard)
    def annotated(self, user: Annotated[User, GuardExtra]) -> dict:
        ...

Note

Doesn't implement application-level route guards; it would be more efficient
to implement this when we have controller/route-level middlewares (see #6)

Although not ideal, this is a temp solution